https://findit-for-me.appspot.com/waterfall/flake?key=ag9zfmZpbmRpdC1mb3ItbWVyxQELEhdNYXN0ZXJGbGFrZUFuYWx5c2lzUm9vdCKOAWNocm9taXVtLmNocm9taXVtb3MvbGludXgtY2hyb21lb3MtcmVsLzExNDA1L3Zpel9jb250ZW50X2Jyb3dzZXJ0ZXN0cy9VMmwwWlZCbGNsQnliMk5sYzNOSWFYUlVaWE4wUW5KdmQzTmxjbFJsYzNRdVVtOXZkRmRwYm1SdmQxUnlZVzV6Wm05eWJTOHcMCxITTWFzdGVyRmxha2VBbmFseXNpcxgBDA

The analysis failed to compile at revision 576661 due to
  -> returned 1
ERROR at //build/config/sysroot.gni:57:5: Assertion failed.
    assert(
    ^-----
Missing sysroot (//build/linux/debian_sid_amd64-sysroot). To fix, run: build/linux/sysroot_scripts/install-sysroot.py --arch=amd64
See //build/config/sysroot.gni:58:9: 
        exec_script("//build/dir_exists.py",
        ^-----------------------------------
This is where it was set.
See //chrome/installer/BUILD.gn:7:1: whence it was imported.
import("//build/config/sysroot.gni")
^----------------------------------
See //BUILD.gn:67:5: which caused the file to be included.
    "//chrome/installer",
    ^-------------------
GN gen failed: 1
# To recreate the file passed to --swarming-targets-file:
% cat > c:\b\swarming\w\ir\tmp\t\tmp5okidw <<EOF
content_browsertests
EOF
%
step returned non-zero exit code: 1

Build cycle containing suspect:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/linux-chromeos-rel/10899